Seaweeds are considered as an important source of phycocolloids such as agar, carrageenan and alginate. Agar and carrageenan are structural polysaccharides present in the cell walls of certain red algae, while alginate is derived from certain brown algae. Seaweed phycocolloids are widely used in various industries as emulsifying agents, gelling agents, stabilizers, thickeners and suspension agents, and thus regarded as value-added products of seaweeds. Traditionally, phycocolloids are extracted from the raw materials harvested from natural resources. However, the increasing utilisation of seaweeds coupled with the unavailability of sufficient raw material in nature eventually led to successful development of different efficient cultivation techniques as well as domestication and selection of strains.